1. Field of the Invention
The present invention relates to a shaft support mechanism used in a skew adjustment mechanism of an optical pick-up unit of an optical disk drive that irradiates the surface of an optical disk such as CD or DVD with a laser beam to perform recording/reproduction.
2. Description of the Related Art
In the operation of irradiating an optical disk such as CD or DVD with a laser beam to read data on the optical disk, if the disk surface is tilted relative to the laser light, signals from the optical disk cannot accurately be reproduced in some cases. To cope with the above problem, there has been employed a skew correction mechanism that tilts an optical pick-up unit relative to the optical disk to perform skew correction. More specifically, the skew correction mechanism supports the optical pick-up unit by a pair of guide shafts and tilts the guide shafts in accordance with the tilt of the optical disk to thereby tilt the optical pick-up unit.
Various types of springs are used to support the guide shafts. For example, in a technique disclosed in Jpn. Pat. Appln. Laid-Open Publication No. 10-255272 (Patent Document 1), a round rod is moved forward or backward to tilt the guide shafts to tilt an optical pick-up unit supported by the guide shaft. In this case, an extension spring is used to force the guide shafts against the round rod.
FIG. 1 shows an example of the optical pick-up unit support mechanism of the optical disk reproduction apparatus, in which a plate spring 12 is used to hold down a guide shaft 11, the plate spring 12 being secured by screwing down a fixing screw 13 on the upper surface. Further, a retainer 14 is provided to prevent the guide shaft 11 being off to the side.
In an example of FIG. 2, a torsion spring 22 is used to hold down a guide shaft 21. A base portion 23 of the torsion spring 22 is secured by a fixture 24 and one end thereof is secured by a stopper 25. Also in this case, a retainer 26 is used to prevent the guide shaft 21 from being off to the side.
However, in the mechanism disclosed in the Patent Document 1, one end of the extension spring needs to be hooked over the guide shaft and the other end needs to be secured to a base plate. This complicates the mechanism to increase manufacturing cost.
Further, the fixing screw 13 and retainer 14 must be provided in the mechanism shown in FIG. 1, and fixture 24 and retainer 26 are indispensable in the mechanism shown in FIG. 2. Thus, the mechanism becomes complicated, leading to increase in manufacturing cost.